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description and function

The
overhand knot is the simplest type of knot and is used to make a knob in a rope, string, or cord. It is used for tying packages, to keep rope ends from fraying, and as a first step in making more complex knots such as the surgeon’s knot and the square knot. An
overhand knot is made by crossing the rope end around the standing part to form a loop, bringing the rope’s end through the loop,...

knot theory

...A measure of the knot’s complexity is the least number of crossings that occur as the knot is moved around in all possible ways. The simplest possible true knot is the trefoil knot, or
overhand knot, which has three such crossings; the order of this knot is therefore denoted as three. Even this simple knot has two configurations that cannot be deformed into each other, although...